Many conventional surgical instruments incorporate cutting blades or the application of energy for transecting and/or cauterizing tissue held within a pair of jaws. A potential difficulty with cutting blades of such instruments is “tissue-tagging” when the blade does not completely cut through all the tissue held in the jaws. This can occur, for example, if the cutting edge of the blade is dull or nicked. Another reason tissue-tagging can occur, or even some bleeding after the tissue is coagulated and cut, is that the tissue is not held firmly enough within the jaws of the instrument as the cutting blade is passed through the tissue held. When tissue is initially clamped within the jaws of the instrument, the clamping force can be very high due to the elasticity of the fluid-containing tissue. But after the tissue has been compressed for a period of time, and then is coagulated, most of the fluid has been driven out of the tissue, with the result that the elasticity of the tissue is greatly reduced. The clamping force on the tissue is also decreased so that the tissue can shift within the jaws as a cutting blade is passed through it. This presents the possibility that not all the tissue will be cut, or the cutting blade will pass through a portion of tissue that is not fully coagulated.
An alternative to using mechanical cutting blades is to use bipolar electrosurgical cutting devices. While such devices offer some advantages over mechanical cutting blades, use of such devices can result in excessive lateral spreading of the thermally affected zone of tissue resulting in damage to healthy tissue, especially if the operator is inexperienced or otherwise not careful.
Accordingly, there is a need for devices and methods for safely, accurately, and efficiently delivering a therapeutically effective amount of monopolar energy to cut and/or coagulate tissue.